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Carbon dioxide capture and storage (CCS) can play a vital role in overcoming global warming challenges and can help to reduce carbon footprint significantly from the environment. Carbon dioxide (CO...

The present study focuses on examining the fate of coal constituents—carbon, sulphur, nitrogen and chlorine from coal blend to coke oven wastewater. Further, the impact of coal constituents and coke making process on wastewater quality has studied and analyzed the effects with plant data. Understanding helps in development of coke oven wastewater quality prediction model using machine learning techniques. A reliable model helps in minimize the operation costs and stable operation of treatment plant. The developed model is implemented and validated using plant scale data obtained for coke plant at Tata Steel Jamshedpur. The model provided accurate predictions of the effluent stream of by product plant, in terms of chemical oxygen demand (COD) and total dissolved solids (TDS) when using coal constituents and coke making process parameters as an input. Implementation strategy of model helps to control the wastewater quality within environmental limit with ease.

Pseudomonas strains are a promising host cell in metabolic engineering for bioconversion, environmental remediation, and most recently for bioelectrochemical applications. This study isolated an electrochemically active Pseudomonas sp. from an anaerobic sludge using a colorimetric and electrochromic WO

In the recent time, the demand of complex castings is continuously increasing, particularly in the field of aerospace, automobile, medical, food processing, and machine tool industry. Investment casting being the oldest manufacturing process is always considered as the most preferred route for producing intricate near-net shape parts. Making undercuts, channels, or passage are the most critical and challenging activity in producing complex shape geometry. For making such castings, cores are used along with the investment molds. In practice cores, in foundries are made from different material such as sand, soluble wax, urea, salt, and ceramic. Among these, the ceramic material-based cores possess better properties compared to any other core materials. Presently, varieties of ceramic cores are used in investment casting foundries. The properties of final cast part significantly affected by the properties of ceramic core, which directly depend on the various core composition. Many researchers have made and tested cores with various ceramic compositions; however, no published research was found which summarizes them in scientifically. This paper presents a study on ceramic core material and core manufacturing process being used in investment casting. The article will be helpful for foundrymen in selecting the appropriate composition of ceramic core material and its manufacturing process based on the part-specific requirements.

This paper is prepared to design microstrip patch aerial for 2.45/5.2 GHz with three shorted pins. The antenna contains patch, shorting pins, substrate, and ground plane. Overall size of antenna is 36 × 44 × 1.57 mm3. It is shown that shorted pins increase the impedance matching of the antenna and its radiation pattern. Resonating frequency of aerial is 2.45/5.2 GHz. As per designs and studies, it depicts that the antenna’s resonant frequency is directly related to shorting pins. The proposed aerial has various applications on resonant frequency and it has Band Width around 20/121 MHz.

This study examined the obligate aerobe, Pseudomonas putida, using acetate as the sole carbon and energy source, and respiration via an anode as the terminal electron acceptor under anoxic conditions. P. putida showed significantly different acetate assimilation in a closed-circuit microbial fuel cell (CC-MFC) compared to an open circuit MFC (OC-MFC). More than 72% (2.6 mmol) of acetate was consumed during 84 hrs in the CC-MFC in contrast to the no acetate consumption observed in the OC-MFC. The CC-MFC produced 150 μA (87 C) from acetate metabolization. Electrode-based respiration reduced the NADH/NAD+ ratio anaerobically, which is similar to the aerobic condition. The CC-MFC showed significantly higher acetyl-CoA synthetase activity than the OC-MFC (0.028 vs. 0.001 μmol/min/mg), which was comparable to the aerobic condition (circa 60%). Overall, electrode-based respiration enables P. putida to metabolize acetate under anoxic conditions and provide a platform to regulate the bacterial redox balance without oxygen.

Hydroxyapatite (HA) having chemical formula Ca10(PO4)6(OH)2, is the main chemical component of human bone tissue (70%). This is the reason why it has been widely engaged in the dental and non-load bearing implantations, to cope up with the bone response as a bioactive material. In this study HA powder was synthesized by wet chemical method, using phosphoric acid (H3PO4) and eggshells. The synthesized HA powder was characterized by X-ray diffraction analysis, Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Fourier transform (FT-IR) spectroscopy. The Thermos gravimetric analysis (TGA-DTA) was also carried out to evaluate the stability of the synthesized HA powder at higher temperatures. The results of the study indicate that sintered (at 900°C) HA powder resembles the feature of pure and single apatite phase having favourable Ca/P ratio ranging from 1.7 to 2.4.

Bacteria is dynamic biocatalyst which is self-regenerating and sustainable in a bioprocess. The respiration and redox state of bacteria are mainly regulated by various external electron acceptors, and significantly influence to the yield/titer of many biosynthesis and biorefinery processes. The cellular redox state is one of the most important factors to control metabolic fluxes and pathways in bioconversion. Conventional strategies for changing the redox state (e.g., the NAD+/NADH ratio) need to provide external oxidants/reductants, such as oxygen, or chemical reductases/oxidases, and carbon source and hydrogen, which are non-sustainable and frequently produce toxic/inhibitory byproducts. In this respect, electrode-based regulation using bioelectrochemical system (BES), has been highlighted for sustainable bioelectricity generation, and in-situ control of bioconversion of substrates such as glycerol, C1 gases etc. The bioelectrochemical regulation of central metabolic fluxes may also trigger gene and enzyme expression. In this study, the increased productivity of the platform chemicals such as 3-hydroxypropionic acid and 1,3-propanediol by using recombinant Klebsiella pneumoniae and E. coli in BES, will be presented as well as recent progress of BES-based bioconversion. The suggested strategy for bacterial redox state regulation not only improves the productivity and yield/titer, but also provides the opportunity for overcoming thermodynamic imbalances in most of bioprocesses. These results could contribute to further improvements in bioprocesses, and could lead to industrial applications for the biorefinery process.

Modern foundries increasingly use chemically bonded no-bake sand cores and molds because they provide ease of molding, good surface finish, and collapsibility. One of the most popular binder systems is alkyd oil urethane no-bake system comprising three parts: alkyd resin, catalyst, and crosslinking agent. Their amounts and ratios can influence mold shrinkage, and thereby dimensional quality of the resulting casting. With rising emphasis on net-shape casting, there is a need to optimize the binder composition to minimize dimensional errors, while achieving the desired bench life, stripping time and hardness. This work investigates the effect of binder composition on the dimensions of chemically bonded sand cores with respect to time. The maximum shrinkage of 0.15% over length was observed when resin content was 2.4% by weight of sand. The rate of shrinkage increased with the amount of catalyst. Measurement of core hardness and reduction in weight, followed by SEM studies, provided a better understanding of the underlying phenomena, especially formation of resin bridges between compacted sand particles and evaporation of solvent. This work is expected to aid in selection of the most appropriate binder composition for a given set of molding process constraints and cast product requirements.

Hydroxyapatite is an attractive biomaterial mainly used in bone and tooth implants because it closely resembles human tooth and bone mineral and has proven to be biologically compatible with these tissues. In spite of this advantage of hydroxyapatite it has also certain limitation like inferior mechanical properties which do not make it suitable for long term load bearing applications; hence a lot of research is going on in the development of hydroxyapatite coating over various metallic implants. These metallic implants have good biocompatibility and mechanical properties. The aim of the present work is to deposit hydroxyapatite coating over stainless steel grade 316 L by pulse laser deposition technique by varying laser energy. To know the effect of this variation, the coatings were than characterized in detail by X-ray diffraction, finite emission-scanning electron microscope, atomic force microscope and energy dispersive X-ray spectroscopy. (C) 2012 Elsevier B.V. All rights reserved.

Chemically bonded sand molds and cores have better mechanical properties and produce more dimensionally accurate castings, compared to green sand molds, and hence are being increasingly preferred for near net shape metal parts. While it is well known that the properties and quality of a mold depend on its material composition and molding process, this has not been investigated well for chemically bonded molds. In this work, the effect of sand grain size, binder percentage and curing time (each varied in three levels) on the mechanical properties (compression strength, shear strength and core hardness) as well as dimensional changes (shrinkage) of no-bake chemically-bonded molds and cores was studied through lab experiments. Their mechanical properties were found to increase with an increase in binder content and curing time; and decrease with increasing grain fineness number. The shrinkage was found to increase with an increase in all three process parameters. The results are explained in terms of bonding and curing phenomena of binders, and evaporation of solvent. These are also supported by SEM analysis of crosslinked resin bridges between sand grains. The findings were incorporated into a multi-objective optimization model to obtain the desired combination of mold properties, which is solved as a linear programming problem. The model and its results were successfully verified through experiments. This work paves the way for automatic optimization of molding parameters of chemically-bonded sand molds and cores, to achieve the desired quality. (C) 2016 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.